1. Technical Field
This invention relates to shampoo formulations used to treat hair loss.
2. Background Art
Most people, to some degree, will experience balding, or alopecia, sometime in their lives. Some estimate that 35 million men in the United States are affected by male pattern baldness or androgenetic alopecia. In general, it appears that the incidence of male pattern baldness correlates with one's age. For example, men in their twenties have a twenty percent incidence of male pattern baldness, those in their thirties have a thirty percent incidence, while those in their forties have a forty percent incidence and so on. One study showed the prevalence of mid-frontal hair loss increases with age and affects 57% of women and 73.5% of men aged 80 and over.
Pattern baldness, or androgenetic alopecia, affecting approximately, one-third of men and women, is the most common type of hair loss. Pattern baldness is characterized by a typical pattern of receding hairline and hair thinning on the crown and can begin as early as the teen years. In men, hair loss begins at the temples and crown and ends with partial or complete baldness. In women, hair loss is generally limited to thinning at the front, sides or crown with complete baldness rarely occurring.
Another type of alopecia, alopecia areata, can be temporary. It can involve hair loss on your scalp or other parts of your body. With alopecia areata, baldness usually occurs in small, round, smooth patches.
Each hair sits in a cavity in the skin called a follicle. The average human head has about 100,000 hair follicles. Each follicle can grow about 20 individual hairs in a person's lifetime. Hair grows about an inch every couple of months. Each hair grows for 2 to 6 years, remains at that length for a short period, then falls out. Most people shed 50 to 150 hairs a day. A new hair soon begins growing in its place.
Baldness in men occurs when the rate of shedding exceeds the rate of regrowth or when the follicle shrinks over time, resulting in shorter and finer hair. Eventually, the shrunken hair follicle may be completely devoid of hair inside, thus failing to grow new hair. Even though the follicles are small, they remain alive, suggesting the possibility of new growth.
Although the mechanism is not clearly understood, genetics and hormones are thought to be involved in pattern baldness. In pattern baldness, heredity appears to play a significant role as pattern baldness on either side of the family increases risk of balding. Excessive amounts of a hormone known as dihydrotestosterone (“DHT”) is also thought to adversely affect hair follicles. DHT binds to androgen receptors in the hair follicles to regulate normal hair growth. Testosterone, a hormone that is present in high levels in males after puberty, is converted to DHT by an enzyme called 5-alpha reductase. As men mature, their bodies produce more testosterone resulting in increased amounts of DHT. Androgen receptor activity increases, slowing down hair production and producing weaker, shorter hair each time the hair regrows.
Other causes of temporary hair loss include disease, diabetes, lupus and thyroid disorder, poor nutrition, medications, certain drugs, medical treatments, childbirth, hair treatments and scalp infections.
Baldness, whether permanent or temporary, cannot be cured. But treatments are available to help promote hair growth or hide hair loss. However, results vary and side effects can be disconcerting.
Minoxidil (Rogaine), available over-the-counter, is a liquid that you rub into your scalp twice daily to regrow hair and to prevent further loss. Some people experience some hair regrowth or a slower rate of hair loss or both. However, new hair resulting from minoxidil use may be thinner and shorter than previous hair. In addition, side effects can include irritation of the scalp.
Finasteride (Propecia) is a prescription medication to treat male-pattern baldness taken daily in pill form. Finasteride inhibits the production of the male hormone dihydrotestosterone. Many people taking finasteride experience a slowing of hair loss, and some may show some new hair growth. Results may take up to several months to manifest. Side effects may include diminished sex drive and sexual function. In addition, Finasteride is not approved for use by women. In fact, it poses significant danger to women of childbearing age and should not be handled by pregnant women.
Surgical procedures, such as hair transplants and scalp reduction surgery, have also been used to treat hair loss. Hair transplants involve taking tiny plugs of skin, each containing one to several hairs, and implanting them into the balding areas. However, effective treatment may require several sessions. Scalp reduction involves decreasing the area of bald skin by surgically removing a balding area and closing the gap with hair-covered scalp. However, these surgical procedures are expensive, can be painful, and may require several procedures. In addition, risks include infection and scarring.
Thus, a safe, effective, cost-effective, easy treatment for preventing hair loss or promoting hair growth is still needed.